Some webpages won't open on any browser!

Hi! So, certain webpages simply won't open! I have a wireless network set up, and my laptop can open them while connected to the same network, my iPod too. I've tried everything , from setting my MTU(gave no results), cleaning my cookies(as FF help suggests), but nothing works. The webpages just say that there was a problem with loading the page, although it loads on an another computer. Help please!